virtual void build(PrimitiveBuilder &) const;
private:
void build_face(PrimitiveBuilder &, const Vector3 &, const Vector3 &, const Vector3 &) const;
virtual void build(PrimitiveBuilder &) const;
private:
void build_face(PrimitiveBuilder &, const Vector3 &, const Vector3 &, const Vector3 &) const;